共查询到20条相似文献，搜索用时 437 毫秒
1.
张秀英 《科技成果管理与研究》2008,(9):86-88
基于3S技术的土地利用动态监测与数据更新已在我国普遍展开,如何快速、便捷地实现土地变化信息的外业核查、勘测与土地数据库的更新是重要的技术关键。本文研究并提出一种基于PDA的外业调查与变更技术方法,能够在外业完成变化图斑的属性核查、数据采集与数据库更新等全部工作,实现了一体化作业,提高外业调查的工作效率,保证数据更新质量。 相似文献
2.
《Information processing & management》2004,40(2):209-221
We present results for automated text categorization of the Reuters-810000 collection of news stories. Our experiments use the entire one-year collection of 810,000 stories and the entire subject index. We divide the data into monthly groups and provide an initial benchmark of text categorization performance on the complete collection. Experimental results show that efficient sparse-feature implementations of linear methods and decision trees, using a global unstemmed dictionary, can readily handle applications of this size. Predictive performance is approximately as strong as the best results for the much smaller older Reuters collections. Detailed results are provided over time periods. It is shown that a smaller time horizon does not appreciably diminish predictive quality, implying reduced demands for retraining when sample size is large. 相似文献
3.
《Information processing & management》2022,59(3):102931
Unsupervised feature selection is very attractive in many practical applications, as it needs no semantic labels during the learning process. However, the absence of semantic labels makes the unsupervised feature selection more challenging, as the method can be affected by the noise, redundancy, or missing in the originally extracted features. Currently, most methods either consider the influence of noise for sparse learning or think over the internal structure information of the data, leading to suboptimal results. To relieve these limitations and improve the effectiveness of unsupervised feature selection, we propose a novel method named Adaptive Dictionary and Structure Learning (ADSL) that conducts spectral learning and sparse dictionary learning in a unified framework. Specifically, we adaptively update the dictionary based on sparse dictionary learning. And, we also introduce the spectral learning method of adaptive updating affinity matrix. While removing redundant features, the intrinsic structure of the original data can be retained. In addition, we adopt matrix completion in our framework to make it competent for fixing the missing data problem. We validate the effectiveness of our method on several public datasets. Experimental results show that our model not only outperforms some state-of-the-art methods on complete datasets but also achieves satisfying results on incomplete datasets. 相似文献
4.
Richard C. Angell George E. Freund Peter Willett 《Information processing & management》1983,19(4):255-261
A nearest neighbour search procedure is described for the automatic correction of misspellings. The procedure involves the replacement of a misspelt word by that word in a dictionary which best matches the misspelling, the degree of match being calculated using a similarity coefficient based on the number of trigrams common to the two words. Experiments with a collection of 1544 misspellings and a dictionary of 64,636 words suggest that the procedure results in the unique identification of the correct spelling for over 75% of the misspellings if the correct form of the word is in the dictionary, and that this figure may be increased to over 90% if near, rather than nearest, neighbours are acceptable. 相似文献
5.
Chun-Yan Liang Li GuoZhao-Jie Xia Feng-Guang NieXiao-Xia Li Liang SuZhang-Yuan Yang 《Information processing & management》2006
A new dictionary-based text categorization approach is proposed to classify the chemical web pages efficiently. Using a chemistry dictionary, the approach can extract chemistry-related information more exactly from web pages. After automatic segmentation on the documents to find dictionary terms for document expansion, the approach adopts latent semantic indexing (LSI) to produce the final document vectors, and the relevant categories are finally assigned to the test document by using the k-NN text categorization algorithm. The effects of the characteristics of chemistry dictionary and test collection on the categorization efficiency are discussed in this paper, and a new voting method is also introduced to improve the categorization performance further based on the collection characteristics. The experimental results show that the proposed approach has the superior performance to the traditional categorization method and is applicable to the classification of chemical web pages. 相似文献
6.
基于混合高斯背景模型的目标检测方法对场景的动态变化具有较强的鲁棒性,其基本思想为:定义每个像素点的分布模型为由多个单高斯模型组成的集合,根据每一个新的像素值更新模型参数,按照一定的准则判断哪些像素点为背景点,哪些为前景点,从而实现对运动目标的检测。 相似文献
7.
The inputs to mathematical models of library operations require periodic updating. The data collection effort necessary for such updating can be quite expensive. However, if the data collected can serve multiple purposes, the costs can perhaps be justified. A management information system offers a vehicle for multiple uses of data and thus, offers an appropriate environment for implementation of models of library operations. Within this paper, the design of a model-based management information system is discussed in terms of mathematical /statistical, information processing, and human factors issues. A prototype system for interlibrary loan networks is discussed. 相似文献
8.
9.
A new method of index term dictionary compression in an inverted-file-orientated database is discussed. A technique of word coding that generates short fixed-length codes obtained from the index terms themselves by analysis of monogram and bigram statistical distributions is described. Transformation of the index term dictionary into a code dictionary preserves a word-to-word discrimination with a rate of three synonyms per 1300 terms, at compression ratio up to 90% and at low cost in terms of the CPU time expenditure. When applied in computer network environment, it offers substantial savings in communication channel utilization at negligible response time degradation. Experimental data for 26,113 index term dictionary of the New York Times Info Bank available via a computer network are presented. 相似文献
10.
11.
Takashi Maeda Yoshio Momouchi Hajime Sawamura 《Information processing & management》1980,16(3):119-127
A new method is described to extract significant phrases in the title and the abstract of scientific or technical documents. The method is based upon a text structure analysis and uses a relatively small dictionary. The dictionary has been constructed based on the knowledge about concepts in the field of science or technology and some lexical knowledge, for significant phrases and their component items may be used in different meanings among the fields. A text analysis approach has been applied to select significant phrases as substantial and semantic information carriers of the contents of the abstract.The results of the experiment for five sets of documents have shown that the significant phrases are effectively extracted in all cases, and the number of them for every document and the processing time is fairly satisfactory. The information representation of the document, partly using the method, is discussed with relation to the construction of the document information retrieval system. 相似文献
12.
《Journal of The Franklin Institute》2019,356(12):6571-6590
In this paper, the distributed consensus problem of leader-follower multi-agent systems with unknown time-varying coupling gains and parameter uncertainties are investigated, and the fully distributed protocols with the adaptive updating laws of periodic time-varying parameters are designed by using a repetitive learning control approach. By virtue of algebraic graph theory, Barbalat’s lemma and an appropriate Lyapunov-Krasovskii functional, it is shown that each follower agent can asymptotically track the leader even though the dynamic of the leader is unknown to any of them, i.e., the global asymptotic consensus can be achieved. At last, a simulation example is given to illustrate the feasibility and efficiency of the proposed protocols. 相似文献
13.
《Journal of The Franklin Institute》2023,360(12):8877-8897
This paper address the distributed bipartite consensus problem of multi-agent systems (MASs) under undirected and directed topologies with dynamic event-triggered (DET) mechanism. The relationship among agents not only collaborative interaction but also competitive interaction are taken into account. A novel DET control protocol is raised with internal dynamic variables to guarantee that each agent can reach the bipartite consensus. Compared with the existing static triggering laws, the introduced DET strategy can significantly enlarge the interval time between two triggering instants. In addition, continuous information transmission in either controller updating or between agent and its neighbors is not demanded, which implies that the communication frequency can be extremely decreased. It is also proven that Zeno behavior does not occur. Finally, two numerical examples verify the validity of the presented theoretical results. 相似文献
14.
Pu-yan Nie 《Journal of The Franklin Institute》2005,342(7):737-748
Stackelberg games, which play extremely important roles in such fields as economics, management, politics and behavioral sciences, can be modelled as a bilevel optimization problem. There exist extensive literatures about static bilevel optimization problems. However, the studies on dynamic bilevel optimization problems are rather scarce in spite of the importance in explaining and predicting some phenomena rationally. In this paper, discrete time dynamic Stackelberg games with open loop complete state are revisited. An example, which comes from law field, is presented as an open-loop Stackelberg game to illuminate the rangy application of game theory. A property based on Bellman's equation is proposed without any restriction about inner point solution for open-loop Stackelberg games in this work. Moreover, we point out that open-loop Stackelberg games perform no better than both feedback and closed-loop dynamic Stackelberg games with complete information, which seems quite valuable to explain some social and economic phenomena. 相似文献
15.
《Information processing & management》2005,41(3):489-506
This paper presents a laboratory based evaluation study of cross-language information retrieval technologies, utilizing partially parallel test collections, NTCIR-2 (used together with NTCIR-1), where Japanese–English parallel document collections, parallel topic sets and their relevance judgments are available. These enable us to observe and compare monolingual retrieval processes in two languages as well as retrieval across languages. Our experiments focused on (1) the Rosetta stone question (whether a partially parallel collection helps in cross-language information access or not?) and (2) two aspects of retrieval difficulties namely “collection discrepancy” and “query discrepancy”. Japanese and English monolingual retrieval systems are combined by dictionary based query translation modules so that a symmetrical bilingual evaluation environment is implemented. 相似文献
16.
Kazuhiro Morita El-Sayed Atlam Masao Fuketra Kazuhiko Tsuda Masaki Oono Jun-ichi Aoe 《Information processing & management》2004,40(6):9325
By the development of the computer in recent years, calculating a complex advanced processing at high speed has become possible. Moreover, a lot of linguistic knowledge is used in the natural language processing (NLP) system for improving the system. Therefore, the necessity of co-occurrence word information in the natural language processing system increases further and various researches using co-occurrence word information are done. Moreover, in the natural language processing, dictionary is necessary and indispensable because the ability of the entire system is controlled by the amount and the quality of the dictionary. In this paper, the importance of co-occurrence word information in the natural language processing system was described. The classification technique of the co-occurrence word (receiving word) and the co-occurrence frequency was described and the classified group was expressed hierarchically. Moreover, this paper proposes a technique for an automatic construction system and a complete thesaurus. Experimental test operation of this system and effectiveness of the proposal technique is verified. 相似文献
17.
There are many cases where it is necessary to store sets of data that are variable in length, and to search these in order to satisfy requests for subsets with a common characteristic. This article presents a file structure that holds an integrated English dictionary used to locate clusters of words for presentation to an intelligent spelling error correction system. Although the emphasis has been on misspelling, the structure presented is capable of handling any other types of lumpy data provided the characteristics used in search requests can be translated into a set of integer numbers. 相似文献
18.
《Information processing & management》1999,35(5):691-711
This paper presents a method for solving the collection fusion problem in hypermedia digital libraries. The proposition which is explored and evaluated is that across document links between hypermedia documents residing in distributed hypermedia collections can supply sufficient useful information to allow effective collection fusion. In contrast to other collection fusion strategies, the link-based fusion strategy does not require a learning phase before it can be utilised and, also does not use any information from remote collections other than the returned list of documents. Because of these characteristics the proposed fusion strategy is suitable for very large and extremely dynamic environments in which other collection fusion strategies (e.g. learning collection fusion strategies) may be inapplicable. Evaluation of the link-based fusion strategy demonstrates that the proposed strategy is more effective and efficient than the uniform strategy which can be applied under the same conditions. 相似文献
19.
《Information processing & management》2023,60(1):103123
Aligning time series of different sampling rates is an important but challenging task. Current commonly used dynamic time warping methods usually suffer from pathological temporal singularity problem. In order to overcome this, we transform the alignment task to a spatial-temporal multi-objective optimization (MOO) problem. Existing MOO algorithms are always inefficient in finding Pareto optimal alignment solutions due to their insufficiency in maintaining convergence and diversity among the obtained Pareto solutions. In light of this, we propose a novel and efficient MOO algorithm Cell-MOWOA which integrates Cellular automata with the rising Whale Optimization Algorithm to find Pareto optimal alignment solutions. Innovative multi-variate non-linear cell state evolutionary rules are designed within Pareto solution external archive to improve the convergence and diversity of the Pareto solutions, and novel whale population updating mechanism is designed to accelerate the convergence to the Pareto front. Besides, new integer whale updating mechanism is presented to transform real-number whale solutions to integer whale solutions. Experimental results on 85 gold-standard UCR time series datasets showed that Cell-MOWOA outperformed six state-of-the-art baselines by 24.53% in average in increasing alignment accuracy and 42.66% in average in reducing singularity. Besides, it achieved outstanding runtime efficiency, especially on long time series datasets. 相似文献